CVE-2017-10983 in FreeRADIUS
Summary
by MITRE
An FR-GV-206 issue in FreeRADIUS 2.x before 2.2.10 and 3.x before 3.0.15 allows "DHCP - Read overflow when decoding option 63" and a denial of service.
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Analysis
by VulDB Data Team • 12/13/2022
The vulnerability identified as CVE-2017-10983 represents a critical memory corruption issue affecting FreeRADIUS server implementations across multiple version ranges. This flaw manifests specifically within the DHCP protocol handling capabilities of the software, where improper input validation leads to buffer overflow conditions during the decoding process of DHCP option 63. The affected versions include FreeRADIUS 2.x releases prior to 2.2.10 and 3.x versions before 3.0.15, making this a widespread concern affecting organizations relying on these server configurations for network authentication and access control services.
The technical nature of this vulnerability stems from inadequate bounds checking during DHCP option processing, particularly when handling option 63 which contains vendor-specific information. When a malformed DHCP packet containing oversized or malformed option 63 data is received by the FreeRADIUS server, the software fails to properly validate the input length before attempting to copy or process the data into fixed-size buffers. This fundamental flaw in input validation creates a classic read buffer overflow condition that can be exploited by remote attackers to cause the server process to crash or behave unpredictably, resulting in denial of service for legitimate network users who depend on the authentication services provided by the affected FreeRADIUS instances.
From an operational impact perspective, this vulnerability poses significant risks to network infrastructure reliability and availability. Organizations utilizing FreeRADIUS servers for network access control, particularly in enterprise environments where wireless networks and wired authentication systems depend on these services, face potential service disruption when exploited. The denial of service condition can affect multiple network users simultaneously, as the compromised server becomes unable to process legitimate authentication requests. This vulnerability directly impacts the CIA triad, specifically compromising availability of critical network services and potentially enabling further attacks if the system is not properly monitored or protected. The issue falls under CWE-121, which specifically addresses stack-based buffer overflow conditions, and aligns with ATT&CK technique T1499.004 for network denial of service attacks.
The exploitation of this vulnerability requires minimal technical expertise, making it particularly dangerous as it can be leveraged by attackers with basic networking knowledge to disrupt network services. Network administrators should consider implementing network segmentation and monitoring to detect anomalous DHCP traffic patterns that might indicate exploitation attempts. The recommended mitigation strategy involves immediate patching of affected FreeRADIUS installations to versions 2.2.10 or 3.0.15 and later, which contain the necessary input validation fixes. Additionally, organizations should implement network access controls to limit DHCP traffic sources and consider deploying intrusion detection systems that can identify malformed DHCP packets targeting this specific vulnerability. Regular security assessments and vulnerability scanning should be conducted to ensure all network infrastructure components remain protected against similar memory corruption vulnerabilities that could potentially be exploited for more severe consequences.